【作者】 王莉莉；

【导师】 张春田；

【作者基本信息】 天津大学 ， 信号与信息处理， 2007， 硕士

【摘要】 随着信息产业的发展,人们在享受网络经济创造的种种便利的同时,也开始触及到因网络普及而带来的各种信息安全问题。上世纪九十年代信息隐藏技术悄然兴起,它可以利用数字内嵌算法将特殊信息隐藏于普通的数字多媒体产品中,在不易被第三方察觉的情况下通过公开信道实现信息的秘密传递。目前随着一些信息隐藏软件在网络上公开发布,信息隐藏技术的使用得以广泛普及,而由此引发的信息安全问题日趋严重,因此学术界和国家相关部门相继加强该领域信息隐藏分析技术的研究。现有信息隐藏对抗技术的研究主要围绕静止图像信息隐藏技术进行,而针对视频信息隐藏分析的研究则尚未完全展开,但丰富的视频资源能为大容量隐蔽通信提供必要的通信环境,因此视频信息隐藏分析技术的研究必将成为各方关注的焦点。现有视频信息隐藏软件可以分为两大类,第一类利用了文件格式上的冗余,包括Steganography,Hider和Max File Encryption等,第二类是将秘密信息嵌入到视频内容中,目前网络上唯一发现的该类公开软件是MSU StegoVideo。第一类软件由于其嵌入信息并未与视频内容相融合,可以轻易的通过文件类型格式分析器将秘密信息提取出来,因此安全性较低;而第二类则需要深入了解其隐藏机制,通过分析其与视频内容的融合方式,设计相应的隐藏分析算法。本文首先简要介绍了信息隐藏的概念,视频信息隐藏的特点、分类、典型算法及其在实际中的应用;其次,讨论了几类比较流行的信息隐藏分析方法,并结合视频信息隐藏分析的特点提出了针对性的设计策略;最后是本文的主体,围绕几种公开视频信息隐藏软件进行深入分析,其中,第四章针对格式级视频信息隐藏软件的特点讨论了相应的格式级隐藏分析方法;第五章则针对MSU StegoVideo视频隐藏软件设计了一种帧差模式检测算法,实验结果表明,该检测算法能够有效的判断一个视频文件是否经过MSU StegoVideo的隐藏处理。更多还原

【Abstract】 The development of IT industry brings much convenience but many information security problems as well. In the 1990s, data hiding techniques arose, which can protect messages by embedding them into innocent-looking cover objects and then transmitting them through open channels without suspects. With the release of some free steganography softwares, information security issues become more secure, and more attention is paid to steganalysis. However, researches mainly focus on attacking image steganography, and little work has been done on video steganalysis till now. But as rich video resources can provide essential channels for secret communication, video steganalytic research is certain to be the focus of many groups.Current video steganography softwares fall into two categories, one of which exploits reduandancy in file formats, including Steganography, Hider, Max File Encryption, etc; the other embeds messages into video contents, including MSU StegoVideo, the only one found at present. For the former, file format checking programes can break it; for the latter, however, combined with deep analysis of its embedding mechanism, targeted attacking schemes need to be designed.This paper firstly introduces the concept of information hiding, describes the features, classification, typical algorithms and applications of video steganography. Secondly, relates the elementary knowledge of steganalysis, and discusses some popular methods of it. Based on characteristics of video steganalysis, corresponding strategies are proposed. Finally comes the body of the author’s work, that is the steganalysis of several public video steganography softwares. Softwares in the former category are analyzed in part 4 of the thesis, while MSU StegoVideo in latter category is analyzed in part 5, according to the specific mode of its embedding mechanism, an inter-frame mode detection algorithm is designed. Experimental resutls show that the proposed scheme can effectively detect whether a video has been processed by MSU or not.更多还原